basic questions - heat, RAM, video

What is a safe temperature for a motherboard/cpu to be running at?
Right NOW, I am running UT2004 at 1600x1200 with all maximum settings, 32 bots on a huge outdoor map (in a window). My CPU is at 57c and my MB is 41c. These are below the 'warning' lines on my temp moniter, just wanted to know your opinions.

Also, i have 2x256MB dual channel RAM, but under control panal-system it only shows that i have 384MB. My assumption here is that my onboard vid-chip (IGP 9100 radeon 9200 based) is taking up that unseen RAM, since it is shared. Is this correct, or should i see 256MB?

Lastly, i'm looking for a graphic card. i've been doing research...the 6800 line seems to outperform the x800. the gf6800 (plain, no GT/Ultra) is what i'm looking at, is there a huge difference between the 6800 and the 6800 GT? It comes down to this as always: What's the most I can get for my money? I'm looking to spend under 400 here if possible.

That seems a little warm. My system is @ 41c now web surfing, and goes to about 46c under gaming load.
Yes the missing RAM is probably being used for the video. This Program called Everest will tell you for sure.
Can't give you too much info on those cards (I'm only running a geforce5200 ) but any of them will blow away what you have now.

no, its not overclocked.
I have a P4 Prescott 3.0 that came with a heatsink in its package. Its an Intel heatsink. It came with it, and its running at max I think. I'm going to try the program suggested above, and apply more thermal paste than is already on there (not a lot).
Thanks for the suggestions so far!

Just remember, for thermal paste, less is more. As long as the whole CPU die is covered, dont apply more. I'm assuming you know this already. 46C is nothing to be really alarmed with, my AMD processor runs around 55 degrees celcius load. Then again, intels have lower tolerances for heat...

woops sorry about that, I don't know where i got 46 from . Yea I would say for a non overclocked pentium 4, that is pretty hot. gotrootdude pretty much sums up what you should do. by the way, how many case fans do you have?

thanks guys.
I have a fan on the bottom pulling air in (the comp is elevated a couple inches) and i have one in back, and a pretty fast PCI fan just for cooling purposes (i don't have a vid card). There should be enough airflow to keep it cool. The two main case fans are pretty cheap, but they move air. Running at standstill (now) the temp is 46-47c. The 57c was when I was running UT2K4 at above, absolute max specifications.

what about vid cards? - is there a massive diff. between the 6800 and the 6800 GT?